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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Copyright (C) 2008-2012, fluid Operations AG<a name="line.2"></a>
<FONT color="green">003</FONT>     *<a name="line.3"></a>
<FONT color="green">004</FONT>     * FedX is free software: you can redistribute it and/or modify<a name="line.4"></a>
<FONT color="green">005</FONT>     * it under the terms of the GNU Affero General Public License as<a name="line.5"></a>
<FONT color="green">006</FONT>     * published by the Free Software Foundation, either version 3 of the<a name="line.6"></a>
<FONT color="green">007</FONT>     * License, or (at your option) any later version.<a name="line.7"></a>
<FONT color="green">008</FONT>     * <a name="line.8"></a>
<FONT color="green">009</FONT>     * This program is distributed in the hope that it will be useful,<a name="line.9"></a>
<FONT color="green">010</FONT>     * but WITHOUT ANY WARRANTY; without even the implied warranty of<a name="line.10"></a>
<FONT color="green">011</FONT>     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the<a name="line.11"></a>
<FONT color="green">012</FONT>     * GNU Affero General Public License for more details.<a name="line.12"></a>
<FONT color="green">013</FONT>     * <a name="line.13"></a>
<FONT color="green">014</FONT>     * You should have received a copy of the GNU Affero General Public License<a name="line.14"></a>
<FONT color="green">015</FONT>     * along with this program.  If not, see &lt;http://www.gnu.org/licenses/&gt;.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    <a name="line.17"></a>
<FONT color="green">018</FONT>    package com.fluidops.fedx.optimizer;<a name="line.18"></a>
<FONT color="green">019</FONT>    <a name="line.19"></a>
<FONT color="green">020</FONT>    import java.util.ArrayList;<a name="line.20"></a>
<FONT color="green">021</FONT>    import java.util.HashMap;<a name="line.21"></a>
<FONT color="green">022</FONT>    import java.util.HashSet;<a name="line.22"></a>
<FONT color="green">023</FONT>    import java.util.List;<a name="line.23"></a>
<FONT color="green">024</FONT>    import java.util.Map;<a name="line.24"></a>
<FONT color="green">025</FONT>    import java.util.Set;<a name="line.25"></a>
<FONT color="green">026</FONT>    <a name="line.26"></a>
<FONT color="green">027</FONT>    import org.apache.log4j.Logger;<a name="line.27"></a>
<FONT color="green">028</FONT>    import org.openrdf.query.algebra.ProjectionElem;<a name="line.28"></a>
<FONT color="green">029</FONT>    import org.openrdf.query.algebra.QueryModelNode;<a name="line.29"></a>
<FONT color="green">030</FONT>    import org.openrdf.query.algebra.Service;<a name="line.30"></a>
<FONT color="green">031</FONT>    import org.openrdf.query.algebra.TupleExpr;<a name="line.31"></a>
<FONT color="green">032</FONT>    import org.openrdf.query.algebra.Var;<a name="line.32"></a>
<FONT color="green">033</FONT>    import org.openrdf.query.algebra.helpers.QueryModelVisitorBase;<a name="line.33"></a>
<FONT color="green">034</FONT>    <a name="line.34"></a>
<FONT color="green">035</FONT>    import com.fluidops.fedx.algebra.NJoin;<a name="line.35"></a>
<FONT color="green">036</FONT>    import com.fluidops.fedx.algebra.StatementTupleExpr;<a name="line.36"></a>
<FONT color="green">037</FONT>    import com.fluidops.fedx.exception.OptimizationException;<a name="line.37"></a>
<FONT color="green">038</FONT>    import com.fluidops.fedx.structures.QueryInfo;<a name="line.38"></a>
<FONT color="green">039</FONT>    <a name="line.39"></a>
<FONT color="green">040</FONT>    <a name="line.40"></a>
<FONT color="green">041</FONT>    /**<a name="line.41"></a>
<FONT color="green">042</FONT>     * Optimizer with the following tasks:<a name="line.42"></a>
<FONT color="green">043</FONT>     * <a name="line.43"></a>
<FONT color="green">044</FONT>     * 1. Find the scope of variables within groups (and store information <a name="line.44"></a>
<FONT color="green">045</FONT>     *    within the node)<a name="line.45"></a>
<FONT color="green">046</FONT>     * <a name="line.46"></a>
<FONT color="green">047</FONT>     * <a name="line.47"></a>
<FONT color="green">048</FONT>     * @author as<a name="line.48"></a>
<FONT color="green">049</FONT>     */<a name="line.49"></a>
<FONT color="green">050</FONT>    public class VariableScopeOptimizer extends QueryModelVisitorBase&lt;OptimizationException&gt; implements FedXOptimizer {<a name="line.50"></a>
<FONT color="green">051</FONT>    <a name="line.51"></a>
<FONT color="green">052</FONT>            public static Logger log = Logger.getLogger(VariableScopeOptimizer.class);<a name="line.52"></a>
<FONT color="green">053</FONT>            <a name="line.53"></a>
<FONT color="green">054</FONT>            protected final QueryInfo queryInfo;<a name="line.54"></a>
<FONT color="green">055</FONT>            protected final Set&lt;String&gt; globalVariables = new HashSet&lt;String&gt;();<a name="line.55"></a>
<FONT color="green">056</FONT>    <a name="line.56"></a>
<FONT color="green">057</FONT>            <a name="line.57"></a>
<FONT color="green">058</FONT>            public VariableScopeOptimizer(QueryInfo queryInfo) {<a name="line.58"></a>
<FONT color="green">059</FONT>                    super();<a name="line.59"></a>
<FONT color="green">060</FONT>                    this.queryInfo = queryInfo;<a name="line.60"></a>
<FONT color="green">061</FONT>            }<a name="line.61"></a>
<FONT color="green">062</FONT>    <a name="line.62"></a>
<FONT color="green">063</FONT>            // TODO variables that are required in FILTER and OPTIONAL (i.e. outside of joins)<a name="line.63"></a>
<FONT color="green">064</FONT>            <a name="line.64"></a>
<FONT color="green">065</FONT>    <a name="line.65"></a>
<FONT color="green">066</FONT>            @Override<a name="line.66"></a>
<FONT color="green">067</FONT>            public void optimize(TupleExpr tupleExpr) {<a name="line.67"></a>
<FONT color="green">068</FONT>                    tupleExpr.visit(this);<a name="line.68"></a>
<FONT color="green">069</FONT>            }<a name="line.69"></a>
<FONT color="green">070</FONT>    <a name="line.70"></a>
<FONT color="green">071</FONT>            @Override<a name="line.71"></a>
<FONT color="green">072</FONT>            public void meet(Service tupleExpr) {<a name="line.72"></a>
<FONT color="green">073</FONT>                    // stop traversal<a name="line.73"></a>
<FONT color="green">074</FONT>            }<a name="line.74"></a>
<FONT color="green">075</FONT>                    <a name="line.75"></a>
<FONT color="green">076</FONT>            <a name="line.76"></a>
<FONT color="green">077</FONT>            @Override<a name="line.77"></a>
<FONT color="green">078</FONT>            public void meet(ProjectionElem node) throws OptimizationException<a name="line.78"></a>
<FONT color="green">079</FONT>            {<a name="line.79"></a>
<FONT color="green">080</FONT>                    globalVariables.add(node.getSourceName());<a name="line.80"></a>
<FONT color="green">081</FONT>                    super.meet(node);<a name="line.81"></a>
<FONT color="green">082</FONT>            }<a name="line.82"></a>
<FONT color="green">083</FONT>            <a name="line.83"></a>
<FONT color="green">084</FONT>            public void meet(Var var) throws OptimizationException {<a name="line.84"></a>
<FONT color="green">085</FONT>                    globalVariables.add(var.getName());<a name="line.85"></a>
<FONT color="green">086</FONT>            }<a name="line.86"></a>
<FONT color="green">087</FONT>    <a name="line.87"></a>
<FONT color="green">088</FONT>            @Override<a name="line.88"></a>
<FONT color="green">089</FONT>            public void meetOther(QueryModelNode node) {<a name="line.89"></a>
<FONT color="green">090</FONT>                    if (node instanceof StatementTupleExpr) {<a name="line.90"></a>
<FONT color="green">091</FONT>                            meetTupleExpression((StatementTupleExpr)node);                  <a name="line.91"></a>
<FONT color="green">092</FONT>                    } else if (node instanceof NJoin) {<a name="line.92"></a>
<FONT color="green">093</FONT>                            meetNJoin((NJoin) node);<a name="line.93"></a>
<FONT color="green">094</FONT>                    } else {<a name="line.94"></a>
<FONT color="green">095</FONT>                            super.meetOther(node);<a name="line.95"></a>
<FONT color="green">096</FONT>                    }<a name="line.96"></a>
<FONT color="green">097</FONT>            }<a name="line.97"></a>
<FONT color="green">098</FONT>    <a name="line.98"></a>
<FONT color="green">099</FONT>            <a name="line.99"></a>
<FONT color="green">100</FONT>            protected void meetTupleExpression(StatementTupleExpr node) {<a name="line.100"></a>
<FONT color="green">101</FONT>                    <a name="line.101"></a>
<FONT color="green">102</FONT>                    // we only get here if this expression is a toplevel expression,<a name="line.102"></a>
<FONT color="green">103</FONT>                    // i.e. it is not part of a join<a name="line.103"></a>
<FONT color="green">104</FONT>                    for (String var : node.getFreeVars())<a name="line.104"></a>
<FONT color="green">105</FONT>                            if (!isProjection(var))<a name="line.105"></a>
<FONT color="green">106</FONT>                                    node.addLocalVar(var);<a name="line.106"></a>
<FONT color="green">107</FONT>            }<a name="line.107"></a>
<FONT color="green">108</FONT>            <a name="line.108"></a>
<FONT color="green">109</FONT>            protected void meetNJoin(NJoin node) {<a name="line.109"></a>
<FONT color="green">110</FONT>    <a name="line.110"></a>
<FONT color="green">111</FONT>                    // map variable names to their parent expressions<a name="line.111"></a>
<FONT color="green">112</FONT>                    Map&lt;String, List&lt;StatementTupleExpr&gt;&gt; map = new HashMap&lt;String, List&lt;StatementTupleExpr&gt;&gt;();<a name="line.112"></a>
<FONT color="green">113</FONT>                                    <a name="line.113"></a>
<FONT color="green">114</FONT>                    for (TupleExpr t : node.getArgs()) {<a name="line.114"></a>
<FONT color="green">115</FONT>                            <a name="line.115"></a>
<FONT color="green">116</FONT>                            // we can only deal with our expressions. In fact,<a name="line.116"></a>
<FONT color="green">117</FONT>                            // t should always be a StatementTupleExpr<a name="line.117"></a>
<FONT color="green">118</FONT>                            if (!(t instanceof StatementTupleExpr)) {<a name="line.118"></a>
<FONT color="green">119</FONT>                                    log.warn("Encountered unexpected expressions type: " + t.getClass() + ", please report this.");<a name="line.119"></a>
<FONT color="green">120</FONT>                                    return;<a name="line.120"></a>
<FONT color="green">121</FONT>                            }<a name="line.121"></a>
<FONT color="green">122</FONT>                            <a name="line.122"></a>
<FONT color="green">123</FONT>                            StatementTupleExpr st = (StatementTupleExpr)t;<a name="line.123"></a>
<FONT color="green">124</FONT>                            for (String var : st.getFreeVars()) {<a name="line.124"></a>
<FONT color="green">125</FONT>                                    if (isProjection(var))<a name="line.125"></a>
<FONT color="green">126</FONT>                                            continue;<a name="line.126"></a>
<FONT color="green">127</FONT>                                    List&lt;StatementTupleExpr&gt; l = map.get(var);<a name="line.127"></a>
<FONT color="green">128</FONT>                                    if (l==null) {<a name="line.128"></a>
<FONT color="green">129</FONT>                                            l = new ArrayList&lt;StatementTupleExpr&gt;();<a name="line.129"></a>
<FONT color="green">130</FONT>                                            map.put(var, l);<a name="line.130"></a>
<FONT color="green">131</FONT>                                    }<a name="line.131"></a>
<FONT color="green">132</FONT>                                    l.add(st);<a name="line.132"></a>
<FONT color="green">133</FONT>                            }                       <a name="line.133"></a>
<FONT color="green">134</FONT>                    }<a name="line.134"></a>
<FONT color="green">135</FONT>                    <a name="line.135"></a>
<FONT color="green">136</FONT>                    // register the local vars to the particular expression<a name="line.136"></a>
<FONT color="green">137</FONT>                    for (Map.Entry&lt;String, List&lt;StatementTupleExpr&gt;&gt; e : map.entrySet()) {<a name="line.137"></a>
<FONT color="green">138</FONT>                            if (e.getValue().size()&gt;1)<a name="line.138"></a>
<FONT color="green">139</FONT>                                    continue;<a name="line.139"></a>
<FONT color="green">140</FONT>                            StatementTupleExpr st = e.getValue().get(0);            <a name="line.140"></a>
<FONT color="green">141</FONT>                            st.addLocalVar(e.getKey());<a name="line.141"></a>
<FONT color="green">142</FONT>                    }               <a name="line.142"></a>
<FONT color="green">143</FONT>            }       <a name="line.143"></a>
<FONT color="green">144</FONT>            <a name="line.144"></a>
<FONT color="green">145</FONT>            private boolean isProjection(String var) {<a name="line.145"></a>
<FONT color="green">146</FONT>                    return globalVariables.contains(var);<a name="line.146"></a>
<FONT color="green">147</FONT>            }<a name="line.147"></a>
<FONT color="green">148</FONT>    }<a name="line.148"></a>




























































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